Double clutch transmission

Abstract

A transmission having two clutches connected between a drive and respective transmission input shafts, one being hollow which supports the other within. A hollow countershaft which supports another countershaft therein. A main shaft arranged coaxially between the inner input shaft and an output shaft. Shifting elements can engage a variety of transmission connections in which transmission elements of the main group couple transmission elements of the range group which can couple the output shaft. The hollow countershaft has three fixed wheels which engage respective loose wheels, and the countershafts are rigidly coupled by a shifting element. With respect to this shifting element: an adjacent loose wheel rotates on and can rigidly couple the main shaft; a remote loose wheel rotates on and can rigidly couple the inner input shaft; and a central loose wheel rotates on and can rigidly couple at least one of the inner input and main shafts.

The invention claimed is: 
     
       1. A dual-clutch transmission with two clutches (K 1 , K 2 ), whose input sides are connected to a drive input shaft (w_an) and whose output sides are respectively connected to one of two transmission input shafts (w_K 1 , w_K 2 ),
 one transmission input shaft (w_K 1 ) is a radially inner solid shaft which is held and able to rotate inside an axially shorter, second transmission input shaft (w_K 2 ) made as a hollow shaft, 
 at least two countershafts (w_V 1 , w_V 2 ) of which one countershaft (w_V 1 , w_V 2 ) is a radially inner solid shaft and is held and able to rotate inside an axially shorter, outer hollow shaft, 
 a drive output shaft (w_ab) arranged axially behind the drive input shaft (w_an), 
 a main shaft (w_HG) arranged coaxially between the inner transmission input shaft (w_K 1 ) and the drive output shaft (w_ab), 
 a multiple-gear main group (HG) in which a plurality of forward-gearwheel planes (Z 1 , Z 2 , Z 3 , Z 4 , Z 5 ) are provided, 
 a multi-gear range group (GP) in drive connection with and located downstream from the main group (HG), 
 a plurality of shifting elements (A, B, C, D, E, F, G, H, I, J) for at least one of shifting transmission elements ( 3 ,  5 ,  7 ,  9 ,  11 , HR, PT, w_K 1 , w_HG, w_V 1 , w_V 2 ) and forming transmission element connections, 
 a first transmission element (w_HG) of the main group (HG) is connected to a first transmission element (SR) of the range group (GP), and a second transmission element ( 9 ) of the main group (HG) is connectable, by an intermediate shifting element (H), to a second transmission element (PT) of the range group (GP) which is connected to the drive output shaft (w_ab), 
 at least three fixed wheels ( 4 ,  6 ,  8 ) are arranged on the outer countershaft (w_V 1 ), each of which meshes with a respective loose wheel ( 3 ,  5 ,  7 ), and the two countershafts (w_V 1 , w_V 2 ) are connectable to one another, in a rotationally fixed manner, by a shifting element (E) that is actuatable on one side, 
 wherein a third loose wheel ( 7 ), closest to the shifting element (E) that is actuatable on one side, is mounted to rotate on the main shaft (w_HG) and is connectable thereto in a rotationally fixed manner, a first loose wheel ( 3 ), furthest from the shifting element (E) that is actuatable on one side, is mounted to rotate on the inner transmission input shaft (w_K 1 ) and is rotationally fixedly connectable thereto, and 
 a central second loose wheel ( 5 ), located between the closest and the furthest loose wheels ( 3 ,  7 ), is mounted to rotate and is connectable, in a rotationally fixed manner, to at least one of the inner transmission input shaft (w_K 1 ) and the main shaft (w_HG). 
 
     
     
       2. The dual-clutch transmission according to  claim 1  wherein the plurality of forward-gear wheel planes of the main group (HG) comprises first, second, third, fourth, and fifth forward-gear wheel planes (Z 1 , Z 2 , Z 3 , Z 4 , Z 5 ) and two transmission ratio steps in the range group (GP), at least eleven powershiftable forward gears (V 1 , V 2 , V 3 , V 4 , V 5 , V 6 , V 7 , V 8 , V 9 , V 10 , V 11 ) can be implemented such that at least one forward gear (V 8 ) can be implemented independently of shift conditions of the range group (GP). 
     
     
       3. The dual-clutch transmission according to  claim 1 , wherein a first forward-gear wheel plane (Z 1 ), of the plurality of forward-gearwheel planes, comprises first and second meshing fixed wheels ( 1 ,  2 ) which form an input constant, the first fixed wheel ( 1 ) is rotationally fixedly connected to the outer transmission input shaft (w_K 2 ) and the second fixed wheel ( 2 ) is rotationally fixedly connected to the inner countershaft (w_V 2 ), a second forward-gear wheel plane (Z 2 ), of the plurality of forward-gear wheel planes, comprises the first loose wheel ( 3 ) and a first fixed wheel ( 4 ) that meshes with therewith, the first loose wheel ( 3 ) of the second forward-gear wheel plane (Z 2 ) is mounted to rotate on the inner transmission input shaft (w_K 1 ) and is connectable thereto, in a rotationally fixed manner, by a first shifting element (A), and the first fixed wheel ( 4 ) is rotationally fixedly attached to the outer countershaft (w_V 1 ), a third forward-gear wheel plane (Z 3 ), of the plurality of forward-gear wheel planes, comprises the second loose wheel ( 5 ) which meshes with a second fixed wheel ( 6 ), the second loose wheel ( 5 ) of the third forward-gear wheel plane (Z 3 ) is mounted to rotate axially between the inner transmission input shaft (w_K 1 ) and the main shaft (w_HG) and is connectable rotationally fixed to the inner transmission input shaft (w_K 1 ) by a second shifting element (B) and is connectable rotationally fixed to the main shaft (w_HG) by a third shifting element (C), and the second fixed wheel ( 6 ) is attached rotationally fixed on the outer countershaft (w_V 1 ), a fourth forward-gear wheel plane (Z 4 ), of the plurality of forward-gear wheel planes, comprises the third loose wheel ( 7 ) which meshes with a third fixed wheel ( 8 ), the loose wheel ( 7 ) of the fourth forward-gear wheel plane is mounted to rotate on the main shaft (w_HG) and is rotationally fixedly connectable thereto by a fourth shifting element (D), and the third fixed wheel ( 8 ) is rotationally fixedly attached on the outer countershaft (w_V 1 ), and a fifth forward-gear wheel plane (Z 5 ), of the plurality of forward-gear wheel planes, comprises a fourth loose wheel ( 9 ) which meshes with a fourth fixed wheel ( 10 ), the fourth loose wheel ( 9 ) of the fifth forward-gear wheel plane is mounted to rotate on the main shaft (w_HG) and is rotationally fixedly connectable thereto by a fifth shifting element (G), and the fifth fixed wheel ( 10 ) is arranged on the inner countershaft (w_V 2 ) in a rotationally fixed manner. 
     
     
       4. The dual-clutch transmission according to  claim 1 , wherein a gradation course is provided which, during a shift sequence, changes from an essentially geometrical gear gradation to an essentially progressive gear gradation. 
     
     
       5. The dual-clutch transmission according to  claim 1 , wherein a planetary gearset with a central sun gear (SR), an outer ring gear (HR) and a planetary carrier (PT) are arranged in the range group (GP), the planetary carrier (PT) supports a plurality of planetary gearwheels (PR) that mesh with the sun gear (SR) and the ring gear (HR), the sun gear (SR) is the first transmission element of the range group (GP), which is connected to the main shaft (w_HG) and functions as the first transmission element of the main group (HG), the planetary carrier (PT) is the second transmission element of the range group (GP) which is rotationally fixedly connected to the drive output shaft (w_ab) and, by the intermediate shifting element (H) arranged axially between the range group (GP) and an adjacent forward-gear wheel plane (Z 5 ), is connectable to a fourth loose wheel ( 9 ) of the forward-gear wheel plane (Z 5 ), which is mounted to rotate on the main shaft (w_HG) and is rotationally fixedly connectable thereto by the fifth shifting element (G), and which functions as the second transmission element of the main group (HG), and the ring gear (HR) is couplable by:
 a first group shifting element (I) to a positionally fixed component ( 14 ), and 
 a second group shifting element (J) to the planetary carrier (PT). 
 
     
     
       6. The dual-clutch transmission according to  claim 1 , wherein a seventh forward gear (V 7 ) is engagable as a highest gear of a lower gear range by engaging a direct connection of the inner transmission input shaft (w_K 1 ) with the main shaft (w_HG) and shifting to a lower transmission ratio step of the range group (GP). 
     
     
       7. The dual-clutch transmission according to  claim 1 , wherein an eleventh forward gear (V 11 ) is engagable as a direct gear by engaging a direct connection of the inner transmission input shaft (w_K 1 ) with the main shaft (w_HG) and shifting to an upper transmission ratio step of the range group (GP). 
     
     
       8. The dual-clutch transmission according to  claim 1 , wherein an eighth forward gear (V 8 ) is engagable, independently of shift conditions of the range group (GP), by engaging a connection between the planetary carrier (PT) of the range group (GP) and a fourth loose wheel ( 9 ) of a fifth forward-gear wheel plane (Z 5 ). 
     
     
       9. The dual-clutch transmission according to  claim 1 , wherein a reversing-gear wheel plane (ZR) is provided, which is arranged axially between a fourth forward-gear wheel plane (Z 4 ) and a fifth forward-gear wheel plane (Z 5 ), the reversing-gear wheel plane (ZR) comprises a reversing loose wheel ( 11 ) and a reversing fixed wheel ( 12 ) and a rotatably mounted rotation direction reversing gearwheel ( 13 ) meshes with the reversing loose wheel ( 11 ) and reversing fixed wheel ( 12 ), the reversing loose wheel ( 11 ) of the reversing-gear wheel plane is arranged to rotate on the main shaft (w_HG) and is connectable rotationally fixedly connectable thereto by a sixth shifting element (F), and the reversing fixed wheel ( 12 ) is arranged rotationally fixed on the inner countershaft (w_V 2 ), whereby six partially powershiftable reversing gears can be implemented. 
     
     
       10. The dual-clutch transmission according to  claim 1 , wherein ten shifting elements (A, B, C, D, E, F, G, H, I, J) are provided so that eight shifting elements (A, B, C, D, E, F, G, H) are associated with the main group (HG) and two shifting elements (I, J) are associated with the range group (GP),
 six of the shifting elements (A, B, C, D, E, F) of the main group (HG) are combined in shifting devices (S 1 , S 2 , S 3 ) that can be actuated on both sides, each with two respective shifting elements (A-B, C-D, E-F), and the two shifting elements (I, J) of the range group (GP) are combined in a further shifting device (S 4 ) that can be actuated on both sides. 
 
     
     
       11. A dual-clutch transmission comprising:
 first and second clutches (K 1 , K 2 ), each of the first and the second clutches having an input side and an output side, the input sides are connected to a drive input shaft (w_an), the output side of the first clutch is connected to an inner transmission input shaft and the output side of the second clutch is connected to an outer transmission input shaft, the inner transmission input shaft (w_K 1 ) is a radially inner solid shaft which is held and able to rotate inside the outer transmission input shaft which is an axially shorter and hollow shaft; 
 outer and inner countershafts (w_V 1 , w_V 2 ), the inner countershaft is a radially inner solid shaft which is held and able to rotate inside the outer countershaft which is an axially shorter, hollow shaft; 
 a drive output shaft (w_ab) arranged axially behind the drive input shaft (w_an), and a main shaft (w_HG) arranged coaxially between the inner transmission input shaft (w_K 1 ) and the drive output shaft (w_ab); 
 a multiple-gear main group (HG) having a plurality of forward-gear wheel planes (Z 1 , Z 2 , Z 3 , Z 4 , Z 5 ) and a multi-gear range group (GP) in drive connection downstream from the main group (HG); 
 a plurality of shifting elements (A, B, C, D, E, F, G, H, I, J) for at least one of shifting transmission elements ( 3 ,  5 ,  7 ,  9 ,  11 , HR, PT, w_K 1 , w_HG, w_V 1 , w_V 2 ) and forming transmission element connections; 
 a main shaft (w_HG) of the main group (HG) is connected to a first transmission element (SR) of the range group (GP); 
 a second transmission element ( 9 ) of the main group (HG) is connectable, via a first shifting element (H), to a second transmission element (PT) of the range group (GP) which is connected to the drive output shaft (w_ab); 
 the outer countershaft (w_V 1 ) comprises first, second and third fixed wheels ( 4 ,  6 ,  8 ), each of the first, the second and the third fixed wheels of the outer countershaft meshing with a respective first, second and third loose wheel ( 3 ,  5 ,  7 ), the outer and the inner countershafts (w_V 1 , w_V 2 ) are connectable, in a rotationally fixed manner, by a second shifting element (E), and the second shifting element being actuated on one side; 
 the third loose wheel ( 7 ) is axially closest to the second shifting element (E), and is mounted to rotate on the main shaft (w_HG) and is connectable so as to be rotationally fixed to the main shaft; 
 the first loose wheel ( 3 ) is axially furthest from the second shifting element (E), and is mounted to rotate on the inner transmission input shaft (w_K 1 ) and is connectable so as to be rotationally fixed the inner transmission input shaft; and 
 the second loose wheel ( 5 ) is arranged axially between the first and the third loose wheels ( 3 ,  7 ), and is mounted to rotate and is connectable, in a rotationally fixed manner, to at least one of the inner transmission input shaft (w_K 1 ) and the main shaft (w_HG). 
 
     
     
       12. The dual-clutch transmission according to  claim 11 , wherein the plurality of forward-gear wheel planes of the main group comprises first, second, third, fourth and fifth forward-gear wheel planes (Z 1 , Z 2 , Z 3 , Z 4 , Z 5 ) and the range group comprises two transmission ratio steps, the first and the second clutches and the plurality of shifting elements being selectively engageable such that at least eleven powershiftable forward gears (V 1 , V 2 , V 3 , V 4 , V 5 , V 6 , V 7 , V 8 , V 9 , V 10 , V 11 ) can be implemented and at least one forward gear (V 8 ) can be implemented independently of shift conditions of the range group (GP). 
     
     
       13. The dual-clutch transmission according to  claim 11 , wherein the plurality of forward-gear wheel planes of the main group comprises first, second, third, fourth and fifth forward-gear wheel planes (Z 1 , Z 2 , Z 3 , Z 4 , Z 5 );
 the first forward-gear wheel plane (Z 1 ) comprises a fourth fixed wheel ( 1 ) that is connected rotationally fixed to the outer transmission input shaft (w_K 2 ) and a fifth fixed wheel ( 2 ) is connected rotationally fixed to the inner countershaft (w_V 2 ), the fourth and the fifth fixed wheels mesh and form an input constant; 
 the second forward-gear wheel plane (Z 2 ) comprises the first loose wheel and the first fixed wheel ( 4 ) that meshes therewith, the first loose wheel ( 3 ) is mounted to rotate on the inner transmission input shaft (w_K 1 ) and is connectable thereto in a rotationally fixed manner by a third shifting element (A), and the first fixed wheel ( 4 ) is attached rotationally fixed to the outer countershaft (w_V 1 ); 
 the third forward-gear wheel plane (Z 3 ) comprises the second loose wheel ( 5 ) which meshes with the second fixed wheel ( 6 ), the second loose wheel ( 5 ) is mounted to rotate axially between the inner transmission input shaft (w_K 1 ) and the main shaft (w_HG) and is rotationally fixedly connectable to the inner transmission input shaft (w_K 1 ) by a fourth shifting element (B) and is rotationally fixedly connectable to the main shaft (w_HG) by a fifth shifting element (C), and the second fixed wheel ( 6 ) is rotationally fixedly attachable on the outer countershaft (w_V 1 ); 
 the fourth forward-gear wheel plane (Z 4 ) comprises the third loose wheel ( 7 ) which meshes with the third fixed wheel ( 8 ), the third loose wheel ( 7 ) is mounted to rotate on the main shaft (w_HG) and is connectable rotationally fixed thereto by a sixth shifting element (D), and the third fixed wheel ( 8 ) is rotationally fixedly attachable on the outer countershaft (w_V 1 ); and 
 the fifth forward-gear wheel plane (Z 5 ) comprises the second transmission element which is a fourth loose wheel ( 9 ) that meshes with a sixth fixed wheel ( 10 ), the fourth loose wheel ( 9 ) is mounted to rotate on the main shaft (w_HG) and is rotationally fixedly connectable thereto by a seventh shifting element (G), and the sixth fixed wheel ( 10 ) is arranged on the inner countershaft (w_V 2 ) in a rotationally fixed manner. 
 
     
     
       14. The dual-clutch transmission according to  claim 11 , wherein a gradation course is provided, which during a sequence, changes from an essentially geometrical gear gradation to an essentially progressive gear gradation. 
     
     
       15. The dual-clutch transmission according to  claim 13 , wherein the range group (GP) is a planetary gearset comprising a central sun gear (SR), an outer ring gear (HR) and a planetary carrier (PT) which supports a plurality of planetary gearwheels (PR) that mesh with the sun gear (SR) and the ring gear (HR);
 the sun gear (SR) is the first transmission element of the range group (GP), and is connected to the main shaft (w_HG) of the main group (HG); 
 the planetary carrier (PT) is the second transmission element of the range group (GP), and is rotationally fixedly connected to the drive output shaft (w_ab) and, by the first shifting element (H) arranged axially between the range group (GP) and an adjacent forward-gear wheel plane (Z 5 ), is connectable to the fourth loose wheel ( 9 ) of the fifth forward-gear wheel plane (Z 5 ), which is mounted to rotate on the main shaft (w_HG) and is connectable rotationally fixed thereto by the seventh shifting element (G), and the ring gear (HR) is couplable by an eighth shifting element (I) to a positionally fixed component ( 14 ) and by a ninth shifting element (J) to the planetary carrier (PT). 
 
     
     
       16. The dual-clutch transmission according to  claim 11 , wherein a seventh forward gear (V 7 ) is engagable as a highest gear of a lower gear range by engaging a direct connection of the inner transmission input shaft (w_K 1 ) with the main shaft (w_HG) and shifting to a lower transmission ratio step of the range group (GP). 
     
     
       17. The dual-clutch transmission according to  claim 11 , wherein an eleventh forward gear (V 11 ) is engagable as a direct gear by engaging a direct connection of the inner transmission input shaft (w_K 1 ) with the main shaft (w_HG) and shifting to an upper transmission ratio step of the range group (GP). 
     
     
       18. The dual-clutch transmission according to  claim 15 , wherein an eighth forward gear (V 8 ) is engagable independently of shift conditions of the range group (GP) by engaging a connection between the planetary carrier (PT) of the range group (GP) and the fourth loose wheel ( 9 ) of the fifth forward-gear wheel plane (Z 5 ). 
     
     
       19. The dual-clutch transmission according to  claim 15 , wherein a reversing-gear wheel plane (ZR) is arranged axially between the fourth forward-gear wheel plane (Z 4 ) and the fifth forward-gear wheel plane (Z 5 ), the reversing-gear wheel plane (ZR) comprises a fifth loose wheel ( 11 ) and a seventh fixed wheel ( 12 ) and, a rotatably mounted rotation direction reversing gearwheel ( 13 ) meshes with the fifth loose wheel ( 11 ) and the seventh fixed wheel ( 12 ), the fifthloose wheel ( 11 ) is arranged to rotate on the main shaft (w_HG) and is connectable rotationally fixed thereto by a tenth shifting element (F), and the seventh fixed wheel ( 12 ) is arranged rotationally fixed on the inner countershaft (w_V 2 ), whereby six, partially powershiftable reversing gears can be implemented. 
     
     
       20. The dual-clutch transmission according to  claim 11 , wherein the first, the second and third, fourth, fifth, sixth, seventh, eighth, ninth and tenth shifting elements (A, B, C, D, E, F, G, H, I, J) are provided, the main group (HG) comprises the first, the second, the third, the fourth, the fifth, the sixth, the seventh, and the eighth shifting elements (A, B, C, D, E, F, G, H) and the range group (GP) comprises the ninth and tenth shifting elements (I, J), the second, the third, the fourth, the fifth, the sixth, the seventh of the shifting elements (A, B, C, D, E, F) of the main group (HG) are combined in first, second and third shifting devices (S 1 , S 2 , S 3 ) that are actuatable on both sides, each with two respective shifting elements (A-B, C-D, E-F), and the ninth and tenth shifting elements (I, J) of the range group (GP) are combined in a further shifting device (S 4 ) that is actuatable on both sides.